The present invention generally relates to the field of computer disk drives and, more particularly, to an actuator arm assembly for a disk drive that includes a pair of actuator arms whose read/write heads are each electrically interconnected with one-piece flex cable that is attached to each of these actuator arms.
There is continuing pressure to reduce the cost of disk drives for computers. One way to reduce disk drive costs is through design simplification of one or more of the main disk drive assemblies. Design simplification may not only reduce material costs and/or production costs, but it may provide desired enhancements to the assembly of the various disk drive components as well which will also tend to reduce the overall cost. Designs which reduce the amount of time required to disassemble a particular disk drive assembly for some type of reworking are also particularly desirable.
A first aspect of the present invention generally relates to an actuator arm assembly for a disk drive. The actuator arm assembly includes at least two actuator arms that each have an upper and lower surface. Hereafter, this will be referred to as first and second actuator arms. Each actuator arm has a suspension that is appropriately attached to its corresponding actuator arm and extends away therefrom. A transducer (e.g., a read/write head) is appropriately mounted on each suspension for exchanging signals with an appropriate computer-readable storage medium (e.g., a hard disk). These two actuator arms and attached components define or are part of an actuator arm stack.
Another component of the actuator arm assembly of the subject first aspect is a flex cable that allows the transducers of the first and second actuator arms to be electrically interconnected with a drive electronics board in a disk drive which may incorporate the actuator arm assembly of the subject first aspect. This flex cable includes first, second, and third flex cable sections. The first flex cable section is attached to the upper surface the first actuator arm and is electrically interconnected with its corresponding transducer. The second flex cable section is attached to the lower surface of the second actuator arm and is electrically interconnected with its corresponding transducer. Finally, the third flex cable section extends between and electrically interconnects the first and second flex cable sections. Notwithstanding this characterization of the flex cable being in multiple sections, the flex cable is in fact integrally formed. The third flex cable section is integrally formed with each of the first and second flex cable sections such that there is no mechanical joint between the first and third flex cable sections, and further such that there is no mechanical joint between the second and third flex cable sections. No soldered connection or the like exists between the first and third flex cable sections, nor between the second and third flex cable sections, to provide the desired electrical interconnection.
Various refinements exist of the features noted in relation to the subject first aspect of the present invention. Further features may also be incorporated in the subject first aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. Both of the first and second actuator arms in the case of the first aspect may be formed by a stamping operation in which at least one and more typically a plurality of actuator arms are stamped from a common sheet of material. The sheet of material may be a laminate or instead may be single piece of material. In any case, the first and second actuator arms may be characterized as stamped components. Another characterization that may be made in relation to the first and second actuator arms of the subject first aspect is that they may be thin structures with planar upper and lower surfaces.
The flex cable associated with the first aspect allows appropriate electrical signals to be sent to and directed from the transducers that are associated with the first and second actuator arms. In one embodiment, at least one preamp is integrally formed with the flex cable. That is, there are no soldered connections or the like between electrical lines/traces and the preamp(s). In another embodiment, the first flex cable section that is attached to the upper surface of the first actuator arm includes a preamp. Having a preamp disposed on an actuator arm reduces the distance between the preamp and at least one transducer, that in turn enhances one or more performance characteristics of the actuator arm assembly.
The electrical interconnection of the flex cable of the first aspect to the noted electronics board may be established by a fourth flex cable section of the flex cable. In this regard, the fourth flex cable section may extend away from either the first or second flex cable section (and thereby away from the first or second actuator arm), and may include a free end that defines an electrical connector (e.g., a pin connector). Once again, the flex cable is integrally formed or of one-piece construction. Therefore, there is no mechanical joint between the fourth flex cable connection and the first or second flex cable section to which the fourth flex cable section interconnects, and including between electrical lines/traces that are on the fourth flex cable section and the corresponding lines/traces that are on the first/second flex cable section.
One way to make the flex cable used by. the subject first aspect is to form an electrical interconnect bus on a common sheet of material that routes one or more electrical interconnect lines or traces in a desired/required pattern. For instance, a film or layer of an appropriate electrically conductive material (e.g., copper) may be deposited or otherwise formed upon a plastic film or other appropriate material (e.g., flexible/pliable), and then patterned to define the desired electrical interconnect bus. It should be appreciated that there would then be no soldered connection or the like between any electrical lines or traces of this electrical interconnect bus throughout the entirety of the flex cable. In any case, this assembly of sorts may then be cut or stamped so as to encompass the entirety of the electrical interconnect bus, and further so as to provide an appropriate configuration for interfacing with the first and second actuator arms, the interconnection therebetween, and for interconnection with the drive electronics board.
The actuator arm assembly of the first aspect may also include a spacer on which each of the first and second actuator arms may be mounted. In one embodiment, this spacer is plastic. Both the first and second actuator arms may include a hole that may be disposed over a hub or the like of the spacer. The spacer would typically include a pair of hubs that extend at least generally away from each other or in opposite directions so that the first and second actuator arms are disposed in spaced relation on opposite sides of the spacer. Features may be incorporated on one or more of the actuator arms and the spacer to interconnect the actuator arms with this spacer, to dispose the actuator arms in a predetermined radial position on the spacer, or both. Preferably, the spacer includes at least one attachment pin and at least one alignment pin for interfacing with the first actuator arm, and at least one attachment pin and at least one alignment pin for interfacing with the second actuator arm. In one embodiment, the attachment pins used by the spacer allow the first and second actuator arms to be detachably interconnected therewith, for instance by including an enlarged head on an attachment pin which is directed entirely through an aligned attachment pin hole on the corresponding actuator arm. In one embodiment, the alignment pins associated with the spacer dispose both the first and second actuator arms on the spacer in a predetermined radial position. One way in which this may be affected is by having a xe2x80x9ctighterxe2x80x9d fit between the alignment pin(s) and its corresponding hole on the first or second actuator arm than exists between attachment pins used by the spacer and their corresponding hole on the first and second actuator arm in the fully assembled condition (e.g., after having passed the enlarged head of the attachment pin entirely through its corresponding attachment pin hole).
A second aspect of the present invention also generally relates to an actuator arm assembly for a disk drive. The actuator arm assembly includes a first actuator arm that has upper and lower surfaces. A first suspension is appropriately attached to the first actuator arm and extends therefrom. A first transducer (e.g., a read/write head) is appropriately mounted on the first suspension for exchanging signals with an appropriate computer-readable storage medium (e.g., a hard disk). The actuator assembly of the second aspect further includes a flex cable that allows the first transducer to be electrically interconnected with a drive electronics board in a disk drive which may incorporate this actuator arm assembly of the second aspect. In this regard, the flex cable includes a first flex cable section that is attached to either the upper or lower surface of the first actuator arm, and further that is electrically interconnected with the first transducer.
Various refinements exist of the features noted in relation to the subject second aspect of the present invention. Further features may also be incorporated in the subject second aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. In one embodiment, the flex cable of the second aspect, and including the first flex cable section, is in the form of a sheet or sheet-like structure. The flex cable associated with second aspect may also incorporate those features of the flex cable discussed above in relation to the first aspect of the present invention.
A third aspect of the present invention also generally relates to an actuator arm assembly for a disk drive. The actuator arm assembly includes a first actuator arm that has upper and lower surfaces. A first suspension is appropriately attached to the first actuator arm and extends therefrom. A first transducer (e.g., a read/write head) is appropriately mounted on the first suspension for exchanging signals with an appropriate computer-readable storage medium (e.g., a hard disk). The actuator assembly of the second aspect further includes a flex cable that allows the first transducer to be electrically interconnected with a drive electronics board in a disk drive which may incorporate this actuator arm assembly. A preamp is integrally formed with this flex cable, and the flex cable is electrically interconnected with the first transducer. In one embodiment, this preamp is disposed on an upper or lower surface of the first actuator arm.
A fourth aspect of the present invention also generally relates to an actuator arm assembly for a disk drive. The actuator arm assembly includes first and second actuator arms. A first suspension is appropriately attached to the first actuator arm, extends away from the first actuator arm, and has a first transducer (e.g., a read/write head) appropriately mounted thereto for exchanging signals with an appropriate computer-readable storage medium (e.g., a hard disk) when the actuator arm assembly of the fourth aspect is incorporated into a disk drive. Similarly, a second suspension is appropriately attached to the second actuator arm, extends away from the second actuator arm, and has a second transducer (e.g., a read/write head) appropriately. mounted thereto for exchanging signals with an appropriate computer-readable storage medium (e.g., a hard disk) when the actuator arm assembly of the fourth aspect is incorporated into a disk drive. Both the first and second actuator arms are detachably interconnected with a spacer via a snap-lock interconnection.
Various refinements exist of the features noted in relation to the subject fourth aspect of the present invention. Further features may also be incorporated in the subject fourth aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. The snap-lock interconnection between the spacer and each of the first and second actuator arms may be provided by one or more attachment pins having an enlarged head that extend completely through an appropriately positioned hole on the corresponding actuator arm. These heads may have a larger diameter than their corresponding attachment pin hole such that the same must be forced therethrough to assemble/disassemble the corresponding actuator arm and spacer.
The above-noted attachment pins that may be utilized by the subject fourth aspect will at least somewhat position the corresponding actuator arm on the spacer in a certain radial position prior to attaching the actuator arm assembly to a pivot bearing or the like of a disk drive that incorporates such an actuator arm assembly. A more precise establishment of a predetermined radial position between the spacer and each of the first and second actuator arms may be established/fixed by using one or more alignment pins. One way to characterize these alignment pins is that the same are structurally different than the above-noted attachment pins. In one embodiment, the alignment pins are of a solid, cylindrical configuration. Another way to characterize these alignment pins is that there is a xe2x80x9ctighterxe2x80x9d fit or smaller clearance between each alignment pin and its corresponding hole on the first or second actuator arm, than between the above-noted attachment pins and their corresponding hole on the first or second actuator arm in the fully assembled configuration (i.e., after having forced the enlarged head of the attachment pin through the corresponding hole in the actuator arm).